Internet Slow Browsing through Proxy

[broberson1]

Hi All,
Not exactly sure the cause this this issue and am seeking a little advice. I posted this question also on Cisco's Netpro.

Have a strange one trying to nail down here.

Senario:
A pc at a remote branch (across a full p-to-p T-1) has extremely slow responses accessing the internet. The PC does use a proxy server to handle the internet requests. There is virtually no load in the T-1 and the issue seems to clear up sometimes. The users at the main site don't experience slowness to the same internet sites while using the same proxy server. To me it really looks like something with the proxy server, but then how do you explain the fact the users at the headquarters don't experience the issue. Also several other branch sites may be experiencing this same issue while other branch locations are not. Could this be a MTU issue or something else? It's strange that users at the main site don't experience the issue, and while the issue is happening the T-1 links to the remotes are at less than 5% utilization. There is nothing fancy no nating or anything with the devices configs.

I did perform a packet capture (see attachment) from the proxy server (10.101.4.19) of the clients request (10.122.59.11) and see gobs of TCP retransmissions.

Any advice from to point me in a direction would be greatly appreciated.

Please visit the below link to get the .pcap attachment.

http://forum.cisco.com/eforum/servl...d=pass_through&location=outline@^1@@.2cd41cd3

Thanks in advance!

 

[North323]

what kind of proxy is it? how are the remote offices connected? EIGRP/BGP? have you tried to do a file copy from remote site to home office? can you post a config of the remote office?

 

[broberson1]

North323,

Thanks for your reply. The remote offices are FULL T-1 hub and spoke (no errors). I've had Cisco TAC look over EVERYTHING and they seem to think it's with the Proxy. The proxies are MS ISA boxes. BTW we have a few (3) of these ISA servers and at any given time the issue could be with any one. At the remote sites if you remove the proxy and browse the issue clears up. On the other had this issue dosen't occur at the main headquarters while its going on at the remotes. It only seems to occur with the sites connected by the T-1's. To help trouble shoot the issue I even created a dummy site at the headquarters using a T-1 X-over cable and one pc at the test site and the same issue happens.

Yes plain old file copys from the remote site to main site over the T-1's are fine.

The WAN protocol is EIGRP. The remote sites are stub's.

Thanks

 

[North323]

what is doing your load balancing? what if instead of removing the proxy, bind it to one ISA, are the results the same?

 

[burtsbees]

What mask are you using? Are these two in the same big *ss subnet???

(10.101.4.19) of the clients request (10.122.59.11)

???

/

tim@tim-laptop ~ $ sudo apt-get install windows
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Couldn't find package windows...Thank Goodness!

 

[broberson1]

The mask are /24's.

The proxy server at 10.101.4.19 subnet mask is 255.255.255.0 as well as the host (10.122.59.11) at the remote end. So no these two host are no in the same big subnet.

Thanks,